U.S. life expectancy has fallen again. Here are three reasons why.

For the second year in a row, life expectancy in the U.S. has fallen — fueled by opioid use, suicide, and — most shockingly — alcohol consumption. A study released Wednesday in the BMJ journal details the United States’ decline from the world leader in life expectancy rates (in the 1960s) to now 1.5 years below the OECD (the Organization for Economic Cooperation and Development) average.

A joint panel of the National Research Council and Institute of Medicine set out to study why America’s new life expectancy, 78.7 years, falls so far below the OECD average of 80.3. The researchers found a wide variety of contributing factors, from obesity and diabetes to homicides and HIV/AIDS. As with studies before it, the researchers found drugs to be a significant contributing factor, citing a 137 percent increase in fatal drug overdoses between the years 2000 and 2014.

In December, the Centers for Disease Control and Prevention released a report directly linking the drop in life expectancy to the opioid crisis. The BMJ study took a wider look at unhealthy behaviors in the U.S., calling the opioid crisis simply the “tip of the iceberg” in the U.S. public health crisis. The researchers cited a 24 percent increase in suicides between 1999 and 2014 as a potential factor as well.

The report’s co-author Steven Woolf, MD, director of Virginia Commonwealth University’s Center on Society and Health and a professor in the Department of Family Medicine and Population Health at VCU School of Medicine, suggested that the results were troubling. “We are seeing an alarming increase in deaths from substance abuse and despair,” Woolf said. “It may not sound like much, but the alarming story is not the amount of the decrease but that the increase has ended [in life expectancy].”

The study found a particular increase in deaths from drugs and alcohol among white Americans. Woolf called this increase “unclear, complex, and not explained by opioids alone.” According to recent federal data, the rate of deaths in America from alcohol abuse is the highest it’s been in 35 years. From 2006 to 2010, excessive alcohol ended the lives of more than 88,000 Americans, according to the Centers for Disease Control and Prevention. On average, in more recent years, alcohol poisoning kills approximately six people per day. In 2010 alone, the economic cost of this excessive alcohol consumption was just below $250 billion.

Woolf and his team suggest that if the U.S. doesn’t take control of the issues that are having a direct impact on life expectancy, it will continue to plummet over time. “Ironically, leaders are outspoken about ending the opioid epidemic and bemoan spiraling and unsustainable health care costs. Solutions to both problems — which involve investment to support struggling families and communities and thereby improve public health — are often rejected,” the authors write. “The consequences are dire: not only more deaths and illness but also escalating health care costs, a sicker workforce, and a less competitive economy. Future generations may pay the greatest price.”